Before entering on the chain of reasoning which led Aristotle to postulate the existence of a personal First Cause, we must explain the difference between his scientific standpoint, and that which is now accepted by all educated minds. To him the eternity not only of Matter, but also of what he called Form,—that is to say, the collection of attributes giving definiteness to natural aggregates, more especially those known as organic species—was an axiomatic certainty. Every type, capable of self-propagation, that could exist at all, had existed, and would continue to exist for ever. For this, no explanation beyond the generative power of Nature was required. But when he had to account for the machinery by which the perpetual alternation of birth and death below, and the changeless revolutions of the celestial spheres above the moon were preserved, difficulties arose. He had reduced every other change to transport through space; and with regard to this his conceptions were entirely mistaken. He believed that moving matter tended to stop unless it was sustained by some external force; and whatever their advantages over him in other respects, we cannot say that the Atomists were in a position to correct him here: for their theory, that every particle of matter gravitated downward through infinite space, was quite incompatible with the latest astronomical discoveries. Aristotle triumphantly showed that the tendency of heavy bodies was not to move indefinitely downwards in parallel lines, but to move in converging lines to the centre of the earth, which he, in common with most Greek astronomers, supposed to be also the centre of the universe; and seeing light bodies move up, he credited them with an equal and opposite tendency to the circumference of the universe, which, like Parmenides and Plato, he believed to be of finite extent. Thus each kind of matter has its appropriate place, motion to which ends in rest, while motion away from it, being constrained, cannot last. Accordingly, the constant periodicity of terrestrial phenomena necessitates as constant a transformation of dry and wet, and of hot and cold bodies into one another. This is explained with perfect accuracy by the diurnal and annual revolutions of the sun. Here, however, we are introduced to a new kind of motion, which, instead of being rectilinear and finite, is circular and eternal. To account for it, Aristotle assumes a fifth element entirely different in character from the four terrestrial elements. Unlike them, it is absolutely simple, and has a correspondingly simple mode of motion, which, as our philosopher erroneously supposes, can be no other than circular rotation.
Out of this eternal unchanging divine substance, which he calls aether, are formed the heavenly bodies and the transparent spheres containing them. But there is something beyond it of an even higher and purer nature. Aristotle proves, with great subtlety, from his fundamental assumptions, that the movement of an extended substance cannot be self-caused. He also proves that motion must be absolutely continuous and without a beginning. We have, therefore, no choice but to accept the existence of an unextended, immaterial, eternal, and infinite Power on which the whole cosmos depends.
So much only is established in the Physics. Further particulars are given in the twelfth book of the Metaphysics. There we learn that, all movement being from possibility to actuality, the source of movement must be a completely realised actuality—pure form without any admixture of matter. But the highest form known to us in the ascending scale of organic life is the human soul, and the highest function of soul is reason. Reason then must be that which moves without being moved itself, drawing all things upwards and onwards by the love which its perfection inspires. The eternal, infinite, absolute actuality existing beyond the outermost starry sphere is God. Aristotle describes God as the thought which thinks itself and finds in the simple act of self-consciousness an everlasting happiness, wonderful if it always equals the best moments of our mortal life, more wonderful still if it surpasses them. There is only one supreme God, for plurality is due to an admixture of matter, and He is pure form. The rule of many is not good, as Homer says. Let there be one Lord.
Such are the closing words of what was possibly Aristotle’s last work, the clear confession of his monotheistic creed. A monotheistic creed, we have said, but one so unlike all other religions, that its nature has been continually misunderstood. While some have found in it a theology like that of the Jews or of Plato or of modern Europe, others have resolved it into a vague pantheism. Among the latter we are surprised to find Sir A. Grant, a writer to whom the Aristotelian texts must be perfectly familiar both in spirit and in letter. Yet nothing can possibly be more clear and emphatic than the declarations they contain. Pantheism identifies God with the world; Aristotle separates them as pure form from form more or less alloyed with matter. Pantheism denies personality to God; Aristotle gives him unity, spirituality, self-consciousness, and happiness. If these qualities do not collectively involve personality, we should like to know what does. Need we remind the accomplished editor of the Nicomachean Ethics how great a place is given in that work to human self-consciousness, to waking active thought as distinguished from mere slumbering faculties or unrealised possibilities of action? And what Aristotle regarded as essential to human perfection, he would regard as still more essential to divine perfection. Finally, the God of pantheism is a general idea; the God of Aristotle is an individual. Sir A. Grant says that he (or it) is the idea of Good.[247] We doubt very much whether there is a single passage in the Metaphysics to sanction such an expression. Did it occur, however, that would be no warrant for approximating the Aristotelian to the Platonic theology, in presence of such a distinct declaration as that the First Mover is both conceptually and numerically one,[248] coming after repeated repudiations of the Platonic attempt to isolate ideas from the particulars in which they are immersed. Then Sir A. Grant goes on to speak of the desire felt by Nature for God as being itself God,[249] and therefore involving a belief in pantheism. Such a notion is not generally called pantheism, but hylozoism, the attribution of life to matter. We have no desire, however, to quarrel about words. The philosopher who believes in the existence of a vague consciousness, a spiritual effort towards something higher diffused through nature, may, if you will, be called a pantheist, but not unless this be the only divinity he recognises. The term is altogether misleading when applied to one who also proclaims the existence of something in his opinion far higher, better and more real—a living God, who transcends Nature, and is independent of her, although she is not independent of him.
We must also observe that the parallel drawn by Sir A. Grant between the theology of Aristotle and that of John Stuart Mill is singularly unfortunate. It is in the first place incorrect to say that Mill represented God as benevolent but not omnipotent. He only suggested the idea as less inconsistent with facts than other forms of theism.[250] In the next place, Aristotle’s God was almost exactly the reverse of this. He possesses infinite power, but no benevolence at all. He has nothing to do with the internal arrangements of the world, either as creator or as providence. He is, in fact, an egoist of the most transcendent kind, who does nothing but think about himself and his own perfections. Nothing could be more characteristic of the unpractical Aristotelian philosophy; nothing more repugnant to the eager English reformer, the pupil of Bentham and of Plato. And, thirdly, Sir A. Grant takes what is not the God of Aristotle’s system at all, but a mere abstraction, the immanent reason of Nature, the Form which can never quite conquer Matter, and places it on the same line with a God who, however hypothetical, is nothing if not a person distinct from the world; while, as if to bewilder the unfortunate ‘English reader’ still further, he adds, in the very next sentence, that ‘the great defect in Aristotle’s conception of God is’ the denial ‘that God can be a moral Being.’[251]
The words last quoted, which in a Christian sense are true enough, lead us over to the contrasting view of Aristotle’s theology, to the false theory of it held by critics like Prof. St. George Mivart. The Stagirite agrees with Catholic theism in accepting a personal God, and he agrees with the First Article of the English Church, though not with the Pentateuch, in saying that God is without parts or passions; but there his agreement ceases. Excluding such a thing as divine interference with nature, his theology of course excludes the possibility of revelation, inspiration, miracles, and grace. Nor is this a mere omission; it is a necessity of the system. If there can be no existence without time, no time without motion, no motion without unrealised desire, no desire without an ideal, no ideal but eternally self-thinking thought—then it logically follows that God, in the sense of such a thought, must not interest himself in the affairs of men. Again, Aristotelianism equally excludes the arguments by which modern theologians have sought to prove the existence of God. Here also the system is true to its contemporaneous, statical, superficial character. The First Mover is not separated from us by a chain of causes extending through past ages, but by an intervening breadth of space and the wheels within wheels of a cosmic machine. Aristotle had no difficulty in conceiving what some have since declared to be inconceivable, a series of antecedents without any beginning in time; it was rather the beginning of such a series that he could not make intelligible to himself. Nor, as we have seen, did he think that the adaptation in living organisms of each part to every other required an external explanation. Far less did it occur to him that the production of impressions on our senses was due to the agency of a supernatural power. It is absolutely certain that he would have rejected the Cartesian argument, according to which a perfect being must exist if it be only conceivable—existence being necessarily involved in the idea of perfection.[252] Finally, not recognising such a faculty as conscience, he would not have admitted it to be the voice of God speaking in the soul.
On the other hand, Aristotle’s own theistic arguments cannot stand for a moment in the face of modern science. We know by the law of inertia that it is not the continuance, but the arrest or the beginning of motion which requires to be accounted for. We know by the Copernican system that there is no solid sidereal sphere governing the revolutions of all Nature. And we know by the Newtonian physics that gravitation is not dependent on fixed points in space for its operation. The Philosophy of the Philosopher Aristotle is as inconsistent with the demonstrations of modern astronomy as it is with the faith of mediaeval Catholicism.
It remains to be seen whether the system which we are examining is consistent with itself. It is not. The Prime Mover, being unextended, cannot be located outside the sidereal sphere; nor can he be brought into immediate contact with it more than with any other part of the cosmos. If the aether has a motion proper to itself, then no spiritual agency is required to keep it in perpetual rotation. If the crystalline spheres fit accurately together, as they must, to avoid leaving a vacuum anywhere, there can be no friction, no production of heat, and consequently no effect produced on the sublunary sphere. Finally, no rotatory or other movement can, taken alone, have any conceivable connexion with the realisation of a possibility, in the sense of progress from a lower to a higher state of being. It is merely the perpetual exchange of one indifferent position for another.
We have now to consider what were the speculative motives that led Aristotle to overlook these contradictions, and to find rest in a theory even less satisfactory than the earlier systems which he is always attacking with relentless animosity. The first motive, we believe, was the train of reasoning, already laid before the reader, by which universal essences, the objects of knowledge, gradually came to be identified with particular objects, the sole existing realities. For the arguments against such an identification, as put forward by our philosopher himself, still remained unanswered. The individuals comprising a species were still too transient for certainty and too numerous for comprehension. But when for the antithesis between Form and Matter was substituted the antithesis between Actuality and Possibility, two modes of evasion presented themselves. The first was to distinguish between actual knowledge and potential knowledge. The former corresponded to existing particulars, the latter to general ideas.[253] This, however, besides breaking up the unity of knowledge, was inconsistent with the whole tenor of Aristotle’s previous teaching. What can be more actual than demonstration, and how can there be any demonstration of transient particulars? The other mode of reconciliation was perhaps suggested by the need of an external cause to raise Possibility into Actuality. Such a cause might be conceived with all the advantages and without the drawbacks of a Platonic Idea. It would be at once the moving agent and the model of perfection; it could reconcile the general and the particular by the simple fact of being eternal in time, comprehensive in space, and unique in kind. Aristotle found such a cause, or rather a whole series of such causes, in the celestial spheres. In his system, these bear just the same relation to terrestrial phenomena that Plato’s Ideas bear to the world of sense. They are, in fact, the Ideas made sensible and superficial, placed alongside of, instead of beneath or behind, the transient particulars which they irradiate and sustain.
The analogy may be carried even farther. If Plato regarded the things of sense as not merely a veil, but an imperfect imitation of the only true realities; so also did Aristotle represent the sublunary elements as copying the disposition and activities of the ethereal spheres. They too have their concentric arrangements—first fire, then air, then water, and lastly earth in the centre; while their perpetual transformation into one another presents an image in time of the spatial rotation which those sublime beings perform. And although we think that Sir A. Grant is quite mistaken in identifying Aristotle’s Supreme Mind with the Idea of Good, there can be no doubt of its having been suggested by that Idea. It is, in fact, the translation of Plato’s abstraction into concrete reality, and the completion of a process which Plato had himself begun. From another point of view we may say that both master and disciple were working, each in his own way, at the solution of a problem which entirely dominates Greek philosophy from Empedocles on—the reconciliation of Parmenides and Heracleitus, Being and Becoming, the eternal and the changeful, the one and the many. Aristotle adopts the superficial, external method of placing the two principles side by side in space; and for a long time the world accepted his solution for the same reason that had commended it to his own acceptance, its apparent agreement with popular tradition and with the facts of experience. It must be confessed, however, that here also he was following the lines laid down by Plato. The Timaeus and the Laws are marked by a similar tendency to substitute astronomy for dialectics, to study the celestial movements with religious veneration, to rebuild on a scientific basis that ancient star-worship which, even among the Greeks, enjoyed a much higher authority and prestige than the humanised mythology of the poets. But for Christianity this star-worship would probably have become the official faith of the Roman world. As it is, Dante’s great poem presents us with a singular compromise between the two creeds. The crystalline spheres are retained, only they have become the abode of glorified spirits instead of being the embodiment of eternal gods. We often hear it said that the Copernican system was rejected as offensive to human pride, because it removed the earth from the centre of the universe. This is a profound mistake. Its offence was to degrade the heavenly bodies by assimilating them to the earth.[254] Among several planets, all revolving round the sun, there could not be any marked qualitative difference. In the theological sense there was no longer any heaven; and with the disappearance of the solid sidereal sphere there was no longer any necessity for a Prime Mover.